ISU-152

When the Tiger and Panther appeared on the Eastern Front in 1943, the Red Army needed a weapon able to smash them at any range. The answer was not a better anti-tank gun but a far bigger one: the 152 mm ML-20S gun-howitzer, mounted in a fixed armoured casemate.

It first appeared as the SU-152 on the KV heavy-tank chassis in early 1943, rushed into service in time for Kursk. When the KV gave way to the new IS (Iosif Stalin) heavy tank, the gun was transferred to that hull, and from late 1943 the definitive ISU-152 entered production at Chelyabinsk.

The ISU-152 carried its 152 mm ML-20S gun-howitzer in a low, well-sloped casemate with a frontal plate around 90 mm thick. The gun fired a colossal 48.8 kg shell; even when its armour-piercing or high-explosive rounds failed to penetrate cleanly, the sheer kinetic shock could blow the turret clean off a Tiger or split its hull welds — the effect that earned the vehicle its nickname “Zveroboy,” the beast-killer.

The price of that gun was a tiny ammunition supply — only about 20 rounds, loaded in two pieces of shell and charge, which held the practical rate of fire to 2–3 rounds a minute. Built on the IS hull at around 46 t and driven by a V-2 diesel of ~520 hp for a road speed near 37 km/h, with a roof-mounted 12.7 mm DShK for air and infantry defence, it was a specialist's weapon: slow to load, short on ammunition and blind to its flanks, but able to demolish almost anything it hit.

The reputation was earned at Kursk in July 1943, and it was earned by very few vehicles. The first regiment equipped with the SU-152, the 1541st Self-Propelled Artillery Regiment under Guards Major A. F. Sankovskiy, had been formed only in May and went into the battle with twelve machines, held in reserve in the north of the salient. They were the only Soviet vehicles that could reliably destroy the new German heavy armour at range, and they were committed where the armour was heaviest.

The regiment’s own report for 8–18 July claimed 7 Tigers, 39 medium tanks and 11 self-propelled guns. That is the figure in the documents; the version that circulates widely — a dozen Tigers and seven Ferdinands — comes from turning those eleven self-propelled guns into Ferdinands, and it does not survive contact with the German side of the ledger: only about 89 Ferdinands existed in the world, all of them at Kursk, and roughly fifty of those returned to Germany in August. Crews on both sides habitually reported every kill as the enemy’s heaviest type, and the ISU-152’s record needs reading with that in mind.

What the gun could do is not in doubt. The 48.8 kg shell did not need to penetrate cleanly: blast alone could tear a turret off its ring, snap tracks or kill a crew through intact armour. The troops named the vehicle for that effect: Zveroboy, the beast-killer, after the German menagerie of Tigers, Panthers and Elefants.

The lineage ran from the SU-152 (KV chassis, 1943) to the ISU-152 (IS chassis, late 1943 onward). A parallel vehicle, the ISU-122, mounted the long 122 mm A-19 gun on the same hull for a higher velocity and larger ammunition load in the pure anti-tank role, and was built in comparable numbers when 152 mm barrels were scarce.

Around 3,500 ISU-152s were produced during the war. The robust design long outlived the conflict, serving in Soviet and client armies and receiving modernisations that kept it in some inventories into the 1970s.

The ISU-152 and its SU-152 predecessor were true multi-role heavy guns. As tank destroyers they ambushed German heavy armour, their huge shells lethal even at long range; as assault guns they led Soviet breakthroughs, blasting bunkers, strongpoints and dug-in guns with high-explosive fire that no medium gun could match.

It was fielded in independent heavy self-propelled artillery regiments of some 21 vehicles, attached to rifle and tank formations to add weight to an attack. But it had to be handled with care: slow reloading, scant ammunition and the vulnerability of a turretless casemate to close-in attack meant it depended on other arms to screen it. Used in its proper role — the ambush and the set-piece assault — it was among the most feared armoured vehicles in Soviet service.

The ISU-152's finest hour came in the urban battles of 1944–45. In the street fighting of Königsberg, Budapest and Berlin, crews ran the heavy guns up behind the infantry and fired point-blank into buildings, collapsing whole facades and strongpoints with a single 48.8 kg shell where a field gun would have battered away for an hour.

It was brutal, close work for which the vehicle was, paradoxically, well suited: the same blast that tore turrets off Tigers brought houses down onto their defenders. In the rubble of the German and Hungarian cities the beast-killer found its second speciality, clearing a path through the last and most stubborn defences of the war.

The ISU-152 was the Red Army's sledgehammer: a 152 mm gun on a heavy chassis that could destroy any German tank, demolish any fortification, and break open any defended town. It embodied the Soviet preference for overwhelming, simple, mass-produced firepower over finesse.

It was not a subtle weapon — short of ammunition, slow to fire and vulnerable on its flanks — but in the assault and the ambush it was unmatched. Around 3,500 were built, and the design answered two separate problems with one gun: it could reduce a fortified building and it could disable a Tiger, and the Red Army needed both from the same vehicle.

• Steven J. Zaloga & Jim Kinnear, IS-2 Heavy Tank 1944–73 (Osprey, New Vanguard) — for the chassis family.
• Maxim Kolomiets, SU-152 and ISU-152.
• Mikhail Baryatinskiy, Soviet Heavy Tanks and Self-Propelled Guns.
• David M. Glantz & Jonathan M. House, The Battle of Kursk (University Press of Kansas).